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TMSR-500 power plants connected to the grid. 2 x 500 MW.

The TMSR-500 is a "Thorium Molten Salt Reactor" nuclear power plant being designed for the Indonesia market by ThorCon. The TMSR-500 is based on a small modular reactor (SMR) that employs molten salt technology. [1] The reactor design is based on the Denatured molten salt reactor (DMSR) design from Oak Ridge National Laboratory[2] and employs liquid fuel, rather than a conventional solid fuel. The liquid contains the nuclear fuel and serves as primary coolant.[3] ThorCon plans to manufacture the complete power plants cheaply in shipyards employing modern shipbuilding construction techniques.

TMSR-500 Design[edit]

ThorCon proposed to use modular shipbuilding production processes in a shipyard to build each TMSR-500 as a completed power station. The TMSR-500 would then be floated and towed on the ocean to the installation site where the walls would be filled with concrete or sand as ballast and shielding. Notably the setup of rebar is not required in this process as steel reinforcement is integral to the hull design.

The TMSR-500 requires as much steel as a medium size, 125,000 dwt Suezmax tanker.[4] The reactor consists of two main components, steam/electrical and nuclear. The steam/electrical component features the same design and cost ($700/kw) of a 500 MWe coal plant. A 1 GWe nuclear component requires less than 400 tons of supercritical alloys and other exotic materials.[5]

The reactor operates at near-ambient pressure, reducing steel requirements by 50% and concrete requirements by 80% versus a conventional reactor. Little of the concrete must be reinforced.[5]

Passive cooling is needed only in the event of overheating, which first stops the reaction, and then triggers freeze valves to drain the reactor. Hazardous fission products iodine-131, cesium-137 and strontium-90 are chemically bound in the reactor salt preventing their release. Each reactor unit operates for four years, cools for four years, and is then replaced. Any fuel recycling would occur offsite.

Each power module has two siloed reactor units generating 557 MW (thermal) yielding 250 MW (electric).[6]


In addition to (low cost) thorium, a 1 GWe reactor initially requires 3,156 kg of 20% low enriched uranium along with 11 kg per day of operation. Every 8 years the fuel must be changed out. At a yellowcake cost of $66/kg, a $7.50 UF
conversion cost and $90 per separative work unit, the levelized fuel cost is 0.53 cents per kilowatt-hour.[5]

Waste product[edit]

Every 8 years 160 tons of spent fuel travel to the recycling facility, consisting of about 75% thorium, with 95% of the balance uranium. Without separation (other than removing the salt), the total fuel waste stream averages about 2 m3 per year.[5]


A 2017 study by the Energy Innovation Reform Project looked at the TMSR-500 and concluded that "if power plants featuring these technologies are able to produce electricity at the average LCOE price projected here (much less the low-end estimate), it would have a significant impact on electricity markets.".[7]

See also[edit]


  1. ^ "ThorCon Advanced Nuclear Reactor -- More Than Worth Its Weight In Salt".
  2. ^ "ThorCon – Powering Up Our World".
  3. ^ Thomas J., Dolan (2017). Molten Salt Reactors and Thorium Energy (1st ed.). Cambridge, MA, USA: Woodhead Publishing. pp. 557–564. ISBN 978-0-08-101126-3.
  4. ^ Wang, Brian (August 27, 2018). "China and Russia looking at 27 floating nuclear reactors but ThorCon and Indonesia could scale to 100 per year". Retrieved 2018-08-29.
  5. ^ a b c d Wang, Brian. "China and Russia looking at 27 floating nuclear reactors but ThorCon and Indonesia could scale to 100 per year". Retrieved 2018-08-30.
  6. ^ Wang, Brian (August 26, 2018). "Global race for transformative molten salt nuclear includes Bill Gates and China". Retrieved 2018-08-30.
  7. ^ EIRP (July 2017). "What Will Advanced Nuclear Plants Cost?".

External links[edit]